module top_module( 
    input [15:0] a, b, c, d, e, f, g, h, i,
    input [3:0] sel,
    output [15:0] out );

    always @(*) begin
        case(sel)
           	4'd0:		out = a;
            4'd1:		out = b;
            4'd2:		out = c;
            4'd3:		out = d;
            4'd4:		out = e;
            4'd5:		out = f;
            4'd6:		out = g;
            4'd7:		out = h;
            4'd8:		out = i;
            default:	out = {16{1'b1}};
        endcase
    end
    
endmodule
